1. Field of the Invention
The present invention relates to a treatment device.
2. Description of the Related Art
There has been generally known an ultrasonic treatment device which grasps a living tissue with a probe for transmitting ultrasonic vibration and with a grasp member, and which coagulates and cuts the grasped living tissue by the ultrasonic vibration of the probe. An example of such an ultrasonic treatment device is disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 11-113922. Jpn. Pat. Appln. KOKAI Publication No. 11-113922 discloses that the value of the section modulus of the probe is higher in the proximal part than in the distal part to improve the strength of the probe.